Feeding sheets into a photocopier

ABSTRACT

A simplified sheet sensor and registration gate for feeding print media sheets from a stack loaded by a user into a receptacle on a photocopier. The gate is pivoted on the mechanism and has a flag attached; and, upon user loading of sheets into the receptacle, the gate is pivoted against a locking arm and the flag is moved to actuate an optic sensor that sheets have been loaded. The locking arm is pivoted on the nudger roll arm and unlocks the gate when the nudger roll is moved down to contact the top sheet in the stack. When the sheet receptacle is unloaded, the gate is pivoted by gravity to the downward position and the locking arm pivots by gravity to reset. If the nudger is raised for sheet jam clearance, the locking arm is pivoted to clear the gate, allowing the gate to drop. The locking resets by gravity.

BACKGROUND

The present disclosure relates to the operation of feeding print media sheets into a photocopier and particularly to such copiers employing a tray or receptacle into which the user loads a stack of sheets to be subsequently automatically fed serially into the photocopier for completion of a desired number of printed copies. In effecting such operations, it is necessary to sense the presence of the print media sheets when loaded in the receptacle by the user and to register the leading edge of the sheets in a stack such that the top sheet of the stack can be correctly positioned for feeding into the copier at a precise location for receiving an image printed thereon.

Heretofore, the detection of the presence of the print media sheets has been accomplished by optical sensors or interrupt sensors activated by flags or indicators physically moved by the media sheets when loaded into the receptacle or tray.

Registration of the leading edge of the media sheet stack has heretofore been accomplished by a vertical wall and lift gate provided to guide the sheets over the wall when feeding. One known technique for enabling feeding of the sheets employs a solenoid for activating a plurality of fingers that pivot out of the paper path to permit feeding. In such arrangements, the fingers are pivoted from above the stack and are prevented from rotation until the sheet nudger is lowered onto the stack for feeding.

This arrangement for sensing, registration and initiating of feeding of sheets from the stack into a photocopier has required the use of costly sensors and mechanisms for registration and feeding of the sheets into the copier. Thus, it has been desired to provide a simplified and less costly construction for a photocopier sheet stack registration and feeding apparatus which provides sufficient locational accuracy for the print media sheets to provide for proper advancement and location of the sheets in the copier to receive an image printed thereon.

BRIEF DESCRIPTION

The apparatus and method of the present disclosure address the above described problem and provide guides on a media sheet tray which are movable for providing lateral sheet registration in the stack to thereby centrally position the sheet stack for subsequent feeding. For feed registration, the user pushes the stack forward such that the leading edge which contacts a registration gate which undergoes a limited movement until making with a stop and subsequently providing a registration surface for the leading edge of the sheets in the stack. The limited movement of the gate between first contact by the leading edge of the sheets in the stack and the gate contacting the stop effects the movement of a flag or indicator away from an optical interrupt sensor which provides a signal to the copier controller that the media sheets are present in the tray or receptacle. Upon receipt of the “sheets present” signal, the machine controller then effects lowering of the nudger into contact with the top sheet in the stack. The lowering of the nudger releases the stop for the registration gate; and, upon activation of the nudger, the movement of the leading edge of the top sheet effects pivoting of the gate upwardly and out of the way to permit feeding of the sheet by the nudger into the copier feeding mechanism.

When the last sheet in the stack has been fed into the copier, the registration gate returns under the force of gravity to its original position. The nudger is then raised to its upward or original position which effects locking of the gate stop for subsequent loading of media sheets for the next job.

In the event that there is a paper jam, upon raising of the nudger for clearance, the gate stop is permitted to pivot under the registration gate permitting the gate to return under gravity to its original position; and, the pivoting lock is further rotated under gravitational force to its original position and is, thus, reset.

The present disclosure describes apparatus and method for economically and simply controlling the sensing and registration of print media sheets in a stack when loaded into the receptacle of a photocopier for commencing a printing job.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an axonometric view of the loading tray or receptacle and feeder for a photocopier;

FIG. 2 is a perspective view of the feeder mechanism for a photocopier showing the sheet registration gate arm;

FIG. 3 is a view similar to FIG. 2 taken from the opposite side with the cover removed to expose the nudger and registration gate locking member;

FIG. 4 is an end view of the gate and nudger mechanism of FIG. 3 with the nudger raised and the gate in the downward media sensing position;

FIG. 5 is a view similar to FIG. 4 showing the gate in the registered or locked position having sensed the presence of media sheets;

FIG. 6 is a view similar to FIG. 5 with the nudger in the downward sheet engaging position;

FIG. 7 is a view similar to FIG. 6 with the registration gate released and moved to the upward position during sheet feeding;

FIG. 8 is a view similar to FIG. 7 showing the last sheet being fed;

FIG. 9 is a view similar to FIG. 8 with the gate and flag returned to the downward original position;

FIG. 10 is a view similar to FIG. 7 showing media sheet jammed in the feeder;

FIG. 11 is a view similar to FIG. 10 with the nudger in the raised position for jam clearance;

FIG. 12 is a view showing the jam cleared and the gate in the fully downward position with the flag and the sensor ready for reloading;

FIG. 13 is a view similar to FIG. 12 showing the pivoting lock lowered under the force of gravity to the locking position; and

FIG. 14 is an enlarged view showing the arrangement of the gate and locking mechanism showing that the forces act through the pivot center of the nudger.

DETAILED DESCRIPTION

Referring to FIG. 1, a feeder mechanism for a copier indicated generally at 10 includes a receptacle indicated generally at 12 having a support platform or tray 14 with a pair of spaced generally parallel guides 16, 18 provided thereon which are laterally moveable on the tray. Each of the guides 16, 18 has a portion thereof (not shown) extending downwardly therefrom into a pair of laterally extending guide slots 20, 22 formed in the tray 14. The guides may be moved toward the center of the tray for registering and aligning the lateral edges of the print media sheets placed in the tray at the time of loading.

Referring to FIGS. 2 and 3, a feeder mechanism is illustrated as having a registration gate or arm 24 pivotally mounted about a pin 26 providing a nudger arm 28 which is pivoted about the axis of a feeder roll 30. The gate extends downwardly through a slot 17 formed in the feeder pan 15.

The nudger arm 28 has attached thereto an axle about which is pivoted a nudger roll 32 which is driven by a gear 34 engaged by idler gear 36 which is driven by gear 38 on the feeder roll 30. The feeder roll is powered separately by a motor controlled by the electronic controller (not shown) for the copier. Referring to FIG. 4, the gate 24 has a flag 40 attached thereto for pivotal movement about stationary pin 26 which is shown in FIG. 4 in the position interrupting a beam in a photodetector 42 disposed for detecting the position of flag 40 and, thus, gate 24.

The gate 24 is shown in FIG. 4 in its fully downward position with the gate arm in the media detecting position; and, the nudger arm 28 is shown in its upward position with the nudger roller 32 away from the tray 14.

A locking arm 44 is pivotally mounted about pin 46 on the nudger arm 28; and, the arm 44 has a finger portion 48 disposed on one side of the pivot for engagement by the gate arm locking portion 50. The end of the arm 44 opposite the locking portion 48 has a notch 52 provided thereon which contacts a stop pin 54 provided on the nudger arm.

With the gate 24 in the fully downward position shown in FIG. 4 and flag 40 engaging the sensor 42, the locking portion or surface 50 of the gate 24 is spaced from the end of the portion 48 of locking arm 44 by a limited amount. The locking arm 44 is pivoted under the force of gravity about pin 46 such that notch 52 contacts stop pin 54. The mechanism is shown in FIG. 4 in the position ready to receive loading of sheets of print media into tray 14 by the user pushing the sheets into contact with arm 24 as indicated by the black arrow and the designation “Media”.

Referring to FIG. 5, the gate 24 is shown as having been moved by the media sheets indicated by the black arrow and a designation “Media” to a position where the locking surface 50 has engaged the end of the locking arm portion 48 of the locking arm 44 such that the gate 24 is locked, in the position shown in FIG. 5, and thus acts as a registration surface for the leading edge of the stack of media sheets. The flag 40 has been raised from the sensor 42 which movement sends a signal from sensor 42 to the controller that the media sheets have been loaded into the tray 14. The nudger arm 28 remains in the upward position with the nudger roll 32 spaced away from the media sheets in the tray 14.

Referring to FIG. 6, the nudger arm 28 is shown as having been lowered to a position such that the nudger roll 32 engages the top sheet in the stack loaded into the tray 14 as denoted by the black arrow labeled “Media” in FIG. 6. The gate 24 has been unlocked by virtue of the end 48 of the locking arm 44 having pivoted downward with the nudger arm 28 to free the contact surface 50 on the gate arm. Thus, in the position shown in FIG. 6, the mechanism is ready for sheets to be fed by the nudger roller 32 into the feed rollers 30, 31 along the tray 14.

Referring to FIG. 7, the nudger roll 32 has been powered as are the feed rollers 31, 32; and, the top sheet of print media is being fed from the stack on the guide pan 15 as indicated by the black arrow and the designation “Media” through the feed rolls 31, 32. The leading edge of the media sheet has caused the gate 24 to be moved to the upward position as shown in FIG. 7 clearing the path for the sheets to be fed into the feed rolls 31, 32.

Referring to FIG. 8, the last of the media sheets in the stack loaded into tray 14 is shown as passing through the feeder rolls 30, 31 by the black arrow labeled “Media”; and, the gate is shown in its upward position with the nudger roll still in the lowered or driving position.

Referring to FIG. 9, upon completion of the print job and unloading of the tray 14 the nudger arm 28 has been raised; and, the passage of the last print media sheet has permitted the gate 24 to drop under the force of gravity to its original position with the flag 40 interrupting the photo beam of sensor 42. The raising of the nudger arm 28 causes the arm 44 to be raised and the locking end portion 48 to remain clear of the contact surface 50 on the gate 24. Thus, the gate 24 is in position to again receive sheets in the tray 14 with a leading edge contacting gate 24 for limited movement in response thereto. The entry of flag 40 into sensor 42 thus signals the controller that the mechanism is in a condition to again receive sheets loaded by the user into tray 14.

Referring to FIG. 10, the mechanism is shown with the nudger arm dropped into a position for feeding media sheets to feed rollers 30, 31 with gate 24 moved to its forward position by a media sheet feeding through the roller 30, 31; however, the media sheet is shown as in a “jammed” or misfed condition wherein the machine has stopped the power to the feed rollers 30, 31 and the nudger roller 32.

Referring to FIG. 11, the mechanism is shown in the condition of FIG. 10 with a print media sheet jammed between rollers 30, 31; however, in the condition in FIG. 11, the nudger arm 28 has been raised to move the nudger roller 32 upward and away from the guide pan 15. The upward movement of the nudger arm 28 has caused the locking arm 44 to be raised by the movement of the pivot pin 46 with the nudger arm 28. This movement causes portion 48 of the locking arm 44 to slide along surface 56 under the locking surface 50 of the gate 24. Thus, the gate 24 is not locked in the upward position but is maintained there by the friction of the media sheet acting on the lower edge of the gate 24.

Referring to FIG. 12, the situation of a jammed media sheet shown in FIG. 11 has been relieved by removal of the jammed sheet; and, the gate 24 is thus allowed to drop under the force of gravity pivoting about the pivot pin 26 and returns to its downward initial position shown in FIG. 12 with the flag 40 again interrupting the beam in the photo optic sensor 42. The nudger arm 28 remains in the upward position away from the feeder pan 15; and, the mechanism is ready to be reset for continuing the job.

Referring to FIG. 13, the state of the mechanism shown in FIG. 12 is further prepared for continuation of the printing job by the rotation of the locking arm 44 about the pin 46 under the force of gravity until the notch 52 in the arm 44 again rests on the locking arm stop pin 54 as shown in FIG. 13. In the position shown in FIG. 13, the locking arm 44 has its end portion 48 again positioned adjacent the gate locking surface 50 and slightly spaced therefrom to permit registration of the media sheets in the stack against the gate 24 which will cause the gate to move to the vertically downward position (see FIG. 5) whereupon surface 50 will contact the end 48 of the locking arm 44 and secure the gate from further movement.

Referring to FIG. 14, the gate 24 is shown in the media sheet stack registration position with the locking surface 50 contacting end 48 of the gate locking 44. The angle of this locking surface 50 ensures that the nudger may be dropped completely un-hindered by the force of gate 24 and ‘locked out’ against locking arm 44. Feeding of media sheets can then resume. The black arrows indicate the line of the reaction force from the sheet stack against the gate, illustrating that the force is biased to the correct side of pin 46 ensuring that the rotation of the locking arm 44 is in the correct direction (clockwise as depicted in this view) to enable the locking arm 44 to be ‘locked out’ shown by the surface of notch 52 in contact with stop pin 54. The sequence of events and mechanism state is shown in Table I.

TABLE I PIVOTING PAPER NUDGER GATE FLAG LOCK PRESENTED UP (AWAY) DOWN IN OPEN REGISTERED UP REGISTER OUT ENGAGED AGAINST POSITION: GATE LOCKED REGISTERED DOWN REGISTER OUT OPEN POSITION (UN- LOCKED) FED BY DOWN AND UP OUT OPEN NUDGER POWERED LAST DOWN DOWN IN OPEN SHEET FED JOB UP DOWN IN RESET COMPLETED OPEN JAMMED DOWN UP OUT OPEN JAM UP FALLS IN OPEN RESET CLEARED DOWN: RESET REGISTERED UP REGISTER OUT ENGAGED AGAINST POSITION GATE (LOCKED) REGISTERED DOWN REGISTER OUT OPEN POSITION (UN- LOCKED)

The method and apparatus of the present disclosure thus provides a media sheet stack registration and feeding operation with a reduced number of parts for the mechanism and combines in the gate the function of sensing the presence of the print media sheets in the stack by the leading edge thereof and the registration of the stack. The gate moves from an initial position to a locked position; and, upon lowering of the nudger arm for powering the nudger roll, the gate lock is released and feeding of the sheets effects movement of the gate to an upward position permitting advancing of the sheets to the feeder rolls. In the event of a paper jam, raising of the nudger roll permits the gate lock to move to a reset position under the force of gravity and the gate itself returns to a closed position under the force of gravity. Upon re-lowering of the nudger arm for continuing the print job, the gate locking mechanism is effective upon the gate sensing the presence of print media sheets in the stack.

It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. 

1. A sheet feeding mechanism for a photocopier comprising: (a) a sheet stack receptacle for user loading a supply of print media with guides for directing sheet feed; (b) a registration gate disposed to be contacted by the leading edge of the sheets to be fed and movable between an open and closed position, the gate moveably responsive upon the sheets contacting the gate to effect a sheet position signal; (c) a sensor operable to detect the sheet position signal and provide an output signal; (d) a releasable stop operable to maintain the gate in a closed position upon contact thereby; and, (e) a sheet nudger moveable between a first position contacting a sheet from a stack to be fed and a second position away from the stack, wherein movement of the nudger to the first position effects release of the stop thereby allowing a sheet, upon urging of the nudger, to effect opening of the gate and upon energization of the nudger permitting sheet movement for feeding into the copier.
 2. The mechanism defined in claim 1, wherein the gate is mounted on the mechanism for pivotal movement.
 3. The mechanism defined in claim 1, wherein the gate includes a flag moveable therewith for effecting the signal.
 4. The mechanism defined in claim 1, wherein the sensor includes an electro-optic device;
 5. The mechanism defined in claim 1, wherein upon completion of sheet feeding from the stack, the gate is moved from the open position under the force of gravity to the closed position.
 6. A method of loading print media sheets from a receptacle into a feeder mechanism comprising: (a) disposing a moveable gate between the sheets and the feeder mechanism, and releasably locking the gate in a closed sheet registering position; (b) sensing movement of the gate and generating a control signal; (c) moving a nudger into a sheet contacting position in response to the control signal and relieving the gate lock; and, (d) energizing the nudger and moving a sheet for effecting movement of the gate to an open position.
 7. The method defined in claim 6, further comprising, when the receptacle is unloaded, moving the nudger to an away position and permitting the gate to close under the force of gravity.
 8. The method of claim 6, wherein the step of sensing movement of the gate includes disposing a flag with the gate and sensing movement of the flag.
 9. The method defined in claim 6, wherein the step of sensing movement of the gate includes electro-optically sensing movement of a flag on the gate.
 10. The method defined in claim 6, wherein the step of locking the gate includes moving a stop member upon movement of the nudger to a position away from the sheets.
 11. The method defined in claim 6, wherein the step of releasably locking the gate in closed position includes moving the gate under the force of gravity to an initial position upon unloading of the receptacle and moving a locking member under the force of gravity. 